Catheter-Induced Coronary Artery Dissection in Spontaneous Coronary Artery Dissection: Incidence, Procedural Characteristics, and Outcomes

Introduction Iatrogenic coronary artery dissection (ICAD) is a rare (<0.2%) but potentially fatal complication of coronary angiography and may be particularly relevant in patients with spontaneous coronary artery dissection (SCAD) due to underlying arterial vulnerability. Material & Methods We analyzed patients enrolled in the Canadian SCAD Study with complete angiographic data and at least one follow-up visit. All included ICADs were catheter-induced and independently adjudicated by two cardiologists. The primary endpoint was a composite of all-cause mortality and recurrent myocardial infarction (MI) during 1080 days of follow-up. Results Among 1141 eligible SCAD patients, 90.3% were female and 2.6% experienced additional ICAD. The right coronary artery was most frequently affected (56.7%) and there was no difference in access site (radial versus femoral; p=0.966) between patients with SCAD only and those with additional ICAD. Most ICADs occurred during the diagnostic part of an urgent angiogram for acute MI and were therefore induced by Judkins catheters (73.3%). Patients with ICAD required emergency revascularization more often than those with SCAD alone (PCI: 60% vs. 1.8%; CABG: 20% vs. 0.8%; both p<0.001). Within the first 10 days, the cumulative incidence of the primary endpoint was markedly higher in the ICAD group (56.7% vs. 4.7%; p<0.001), whereas event rates beyond the 10-day landmark were low and comparable (7.7% 5.2%; p = 0.723: Figure 1). Conclusion ICAD occurs with increased frequency in patients with SCAD despite an overall limited PCI exposure and is also associated with worse short-term outcome. This highlights the concepts of an underlying arterial fragility as potential shared mechanism predisposing to both spontaneous and iatrogenic dissections.